Transformer.



Patented July 9, I90l.

. J. .1. FRANK.

TRANSFORMER.

(Application filed Mar. 25, 1901.)

(No Model.)

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UMTED STATES PATENT OFFICE.

JOHN J. FRANK, OF SCHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, OF NEW YORK.

TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 677,970, dated July 9, 1901.

Application filed March 25, 1901. Serial No. 52,757. (No model.)

To ctZZ whom it may concern/.-

Be it known that 1, JOHN J. FRANK, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Transformers,((lase No. 1,864,) of which the following is a specification.

This invention relates to improvements in transformer structures, with special reference to means for securing the cores and windings in position in the usual metallic casings and to means for moving them in and out of the casing. 7

Prior to the invention crude and imperfect devices were commonly used for this purpose and the invention was made in the face of information that it was impossible to improve the existing means on account of the difficulties inherent in the nature of the apparatus. First among these difficulties was the fact that the core and windings cannot be made to fit the metallic casing because they are the parts which become heatedin operation and it is necessary that as much of theirsurfaces as possible should be exposed to the action of a'cooling medium, such as oil or an air-blast. In the second place, no securing parts can be permitted to permanently project from the inner surface of the casing whereby the windings would be injured when the core and windings were inserted in or removed from the casing. Furthermore, if securing means independent of the casing be employed it must be such as'to leave large portions of the core and windings exposed, so that the heatgenerated in them can be readily dissipated. Also the means should be such that the parts can be readily inserted in or removed from the casing. In addition, the parts should be so firmly secured in the casing that they can neither have any lateral movement due to the tend ency to vibrate during operation, nor to shocks received in shipment, nor any movement longitudinally in the casing due to the latter cause.

Until the practical application of this invention the core and windings were held in place by a board which rested on the bottom of the casing and which was provided with grooves for the reception of the laminated core. This board covered a large part of the core which should have been exposed and was an unsatisfactory device. The parts were removed from and inserted in the casing by hooking to the upper portion of the parts. Sometimes the supporting board would be lifted with the core and windings; but much more frequently it would remain in position in the bottom of the casing or drop off, owing to the weight of the sustained parts, and when the latter were again lowered in the casing the core laminae, being made of flexible sheet metal, would spread and curl up, so that the magnetic circuit would be impaired and the cross connecting-leads be liable to be abraided to short-circuit the apparatus.

In transformer structures made in accordance with this invention the above-named difficulties are surmounted, and to this end there are provided clamps which securely grip the core laminae, support the windings, and hold the structure horizontally and vertically immovable in the casing. The clamps also provide supports for the porcelain bushings of the primary and secondary leads and provide a means for lifting the structure from the casing without subjecting the parts to any objectionable strains.

Of the drawings, Figure 1 is a vertical section'of a transformer-casing with its cover in place, showing in elevation the operating parts of the transformer in proper position within the casing; and Fig. 2 is a plan of the casing with the cover removed, showing the top of the operating parts of the transformer.

Numerals are employed to designate the old parts of the apparatus, and the'parts to which the invention relates arerepresented by letters.

The casing is shown at 1 and is formed with a wave-like outline in order to provide maximum radiating-surfaces.

the upper opening of the casing and is secured thereto in a manner hereinafter described. As shown, the inner diameter of the top of the casing is larger than that of the bottom, and in transformers of this type A cover 3 closes 5 the casing is filled with oil, which conducts heat from the core and coils to the wave-like surfaces of the casing. Cast integral with the casing are lugs at by which the entire apparatus can be lifted, and there are also provided brackets 14-, by which the casing may be secured to a suitable support. A screwplug 5 is provided to permit the oil to be drawn from the casing when desired.

The core 0 is rectangular in outline and is formed of sheet-metal strips of laminze, as shown in Fig. 2. The core may be constructed with fou r independent sides orlegs, or it may be U-shaped, with an independent end piece to complete the magnetic circuit. Upon the longer legs of the core are wound the secondary coils S, which are connected in series by the leads 10 and are provided with leads 11, which pass through porcelain insulators I to insulators (5, Fig. 2, and thence outside the casing. The primary coils are formed in separate sections P, surrounded by bands 7, which are slipped on over the secondary coils before the end piece of the core 0 is put in place and are connected in series by short leads 8. The lead 9 connects in series the two cylinders thus assembled, and two leads 12 extend from the ends of the winding as a whole through bushings l to bushings 13,Fig. 2, and thence to the outside of the casing. The primary coils may be forced on over the secondary coils or they may be adapted to slip readily thereover and be held in place by wedges to. Both the secondary and primary coils are covered, as usual,with suitable insulation, such as tape. As shown in Fig. 1, the entire surfaces of the primary coils and a part of the secondary coils are exposed to the oil or other cooling medium, and a large proportion of the core which extends beyond the windings is also exposed to the oil. As shown in Fig. 2, a considerable proportion of the edges of the core laminae are exposed and the oil may be permitted access to the edges of laminae which are not visible.

A board G serves as a support for the windings, which rest on strips of soft felt F on top of the board, the felt serving to prevent injury to the insulation of the windings by the vibration occurring during operation. This board rests on the lower end sheets of the core 0, as shown in Fig. 1, and is perforated for the reception of the vertical legs of the core, as shown by the dotted lines. The drawings show a rather small transformer, and in the larger sizes, where more heat is generated,the single board is replaced by a plurality of wooden blocks in order that a greater extent of the surface of the core may be exposed to the oil. The corners of the board G are cut, as shown at G, and these corners are gripped by lugs H, which project from clamping members M, drawn together by bolts B. There are two of these lugs H. on each clamping member, and they are disposed d iagonally,so that the supporting-board adapted to engage in these sockets.

Ga a

G is prevented from all lateral movement. These two clamping members are cut away in the same manner as those shown in Fig.2, so that a considerable extent of the edges of the core laminae are exposed to the oil. The clam ping members are provided with legs L, which are adapted to rest on the bottom of the transformer-casing 1, and lugs D are formed integral with the clamping members. These lugs D, as shown in Fig. 2, are adapted to [it against the sides of the bottom of the casing to prevent all lateral movements of the clamping members, and they also serve to guide the structure and keep it central as it is lowered into the casing, which has a graduallydecreasing diameter. Lugs K are also formed integral with the clamps, and they are formed with slots through which pass the wire-cable sling K, by which the parts are removed from or inserted in the casing. The clamps M when brought together by the bolts B not only grip the support G by means of the lugs H, but they also grip the ends of the core laminae O to form a strong and rigid support for the same and also to prevent the sheetmetal laminze from spreading and bending or curling.

The upper part of the core and windings are secured in a manner similar to that above described. Two clamping members M are adapted to grip the core laminae O in the manner just described and are brought together by bolts B. Both the upper and lower clam ping members can be made standard for a single-size casing which may contain dilferent transformer structures having a wide range of sizes. For instance, when a wider core is used the boltsB will be spaced farther apart. Of course the clamping members are suitably insulated from the core 0, and when a thinner core is used the extra space may be taken upbyadditionalinsulation. Theupperclamping members M differ from the lower clamping members M in that each member is cast with a part of a socket U, so that when the members are assembled they form a complete socket. These sockets U have a curved interior, as shown in Fig. 1, and washers V, having a correspondingly-cnrved outline, are Portions Z of the casing are cored out for the reception of bolts X, having a suitable portion Y adapted to engage in the cored out portions. Nuts W, threaded to these bolts, engage the washers V, and as the cored-out portions of the casing are at points above the sockets U when the nuts W are screwed down upon the washers the transformer parts are forced downwardly in the casing and securely held in that position to prevent all longitudinal movement of the parts and also lateral movements in the direction of a line between the two sockets U. The curved sockets of course provide for the adjustment of the nuts W. It should be noted that the bolts X are entirely independent parts and the clamping members and are provided with exterior grooves for the reception of wedges J, which are driven in between the grooves and the casing. These lugs Q are provided with perforations L for the reception of the upper ends of the sling K, which are leaded or soldered in the perforations, so that theportions of the sling between the upper and lower clamping members are substantially rigid and are the equivalents of bolts or other rigid mechanical connections.

It may be noted here that the nature of the clamping members used as a supporting and securing means permits their being perforated, so that only very small portions of the parts which become heated are not exposed to the action of the oil.

As shown in Fig. 1, a wedge or block E is interposed between the clamping members M and the secondary windings S. Since the clamping members gripping the core 0 are held from longitudinal movement by the bolts X, this block E serves to prevent the windin gs from having any longitudinal movement. A strip of soft felt F is interposed between the blocks and the windingE in order to prevent abrasion of the insulation, as was described with respect to the strip of felt F between the lower support Gand the windings.

Holders N and N extend from the clamping members M and are provided with a lower inner annular flange or lug 0, Fig. 2. These collars support the insulating-bushings I and I, through which pass the leads for the windings. Two different methods are employed for securing these bushings in the holders. The bushing I (shown at the left) is formed with a collar Q, which rests upon the flange O of the holder, and a suitable soft metal is pouredin the holder around the bushing to secure the latter in position. The bushing 1 (shown at the right) is provided with an annular groove T, and after the bushing has been inserted in the holder a suitable soft metal is poured into the latter upon its annular curve T, thereby securing the bushing in place. As shown in Fig. 2 with respect to the bushing Iat the right, the edges R of the holder N are turned in at their ends to abut against the bushing 1, thereby preventing the soft metal from running out of the holder. In some cases the holders N and N are cast integral with the clamping members M, and in other cases where it is desired to adjust the holders they are made separately and secured to the clamping members by suitable bolts. With this exception there are no machined parts of the clamping members except the holes for the bolts B, which draw them together.

It will be evident from the above description that the core and windings are securely held within the casing, so that they can have no possible movement, that a maximum amount of their surfaces is exposed to the oil, and that the transformer-casing is not obstructed in any way. The clamping members support both the core-laminae and the windings, hold the structure horizontally and vertically immovable, and provide supports for the insulating-bushings for the leads. In addition to these bushings a connection-board might be supported on the clamping members. A further thing is accomplished which is of very great importance in practice, and this is the adaptation of the structure which permits the removal of the parts by the sling K. A book can be inserted in the upper loops of the sling and the entire core and windings be readily removed from the casing. By this means the sling sustains the weight of the parts, which is so evenly distributed that the different parts are not subjected to serious strains.

The cover 3 is secured to the casing by bolts 1), the heads of which engage in recesses in the casing. An annular rim r is formed on the top of the cover around the bolt-hole. A nut n, having its upper end closed and pro vided with a petticoat O, is threaded to the bolt, and when the parts are in position no moisture can creep up into the hole and down through the latter into the cover, which was formerly the case before this preventative was adopted.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a transformer structure, the combination with the core and windings, of a bottom support therefor which is adapted to rest on the bottom of the transformer-casing, and a mechanical connection extending upwardly from said support, which connection sustains the weight of the parts when the transformer is moved by means of said connection into or out of the casing.

2. In a transformer structure, the combination with the core and windings, of a bottom support therefor which is adapted to rest on the bottom of the transformer-casing, and a sling extending under said support, which sling sustains the weight of the parts when the transformer is moved by means of the sling into or out of the casing.

3. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae and are adapted to rest on the bottom of the transformer-casing.

4. In a transformer structure, the combination with the core and windings thereon, of a support for the windings, and clamping members on which said support rests, which members clamp the support to prevent its lateral movement and are adapted to rest on the bottom of the transformer-casing.

5. In a transformer structure, the combination with the laminated core and windings thereon, of clamping members which grip the core laminae and windings and are adapted to rest on the bottom of the transformer-casing and to engage the sides thereof.

6. In a transformer structure, the combination with the laminated core and windings thereon, of clamping members which grip the core laminae and windings, are-adapted to rest on the bottom of the transformer-casing, and are provided with lateral lugs which engage the sides of the casing to prevent lateral movement.

7. In a transformer structure, the combination with the core and windings thereon, of a support for the windings, and clamping members which rest on the bottom of the transformer casing and are provided with lugs which grip said winding-support.

8. In a transformer structure, the combination with the core and windings, of a support for the windings, and clamping members provided with diagonally-disposed lugs which grip the winding-support to prevent its movement in any lateral direction.

9. In a transformer structure, the combination with the laminated core and windings thereon, of a support for the windings, clamping members which grip the core laminae and are adapted to rest on the bottom of the transformer casing, and lugs on said members which grip said winding-support.

10. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae and are adapted to rest on the bottom of the transformer-casing, and bolts for drawing said parts together.

ll. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae and are adapted to rest on the bottom of the transformer-casing, and mechanical connections extending upwardly from said members, which connections sustain the weight of the parts when the transformer is moved into or out of the casing.

12. In a transformer structure, the combination with the laminated core and windings thereon, of a bottom support therefor which is adapted to rest on the bottom of the transformer-casing and is provided with holes, and a sling which passes through said holes and sustains the weight of the parts when the structure is moved in or out of the casing.

13. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae to prevent spreading, and bolts which draw said parts together.

Ll. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae, and

e a zero grooved lugs on said members for the reception of wedges between the lugs and the transformer-casing.

15. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae, and holders on said members for the reception of insulating-bushings for the leads from the windings.

16. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae, and. holders formed integral with said members for the reception of insulating-bushings for the leads.

17. In a transformer structure, the combination with the laminated core, of clamping members which grip the core laminae, bushing-holders, and insulating-bushings leaded in said holders.

18. In a transformer structure, the combination with the laminated core, of clamping members which grip the core, holders having inner annular lugs, and insulating-bushings leaded in said holders.

19. In a transformer structure, the combination with alaminated core, of a bottom support therefor which is adapted to rest on the bottom of the transformer-casing, clamping members which grip the core laminae and are provided with slots, and a sling extending under said bottom supports and through the slots in said clamping members' 20. In a transformer structure, the combination with the laminated core, of a bottom support therefor which is adapted to rest on the bottom of the transformer-casing, clamping members which grip the core laminae and are provided with slots and a sling extending through said bottom support and loaded in the slots in said clamping members.

21. In a transformer, the combination with the laminated core, of a casing therefor, clamping members which grip the core laminae, and bolts engaging said members and a cored portion of the casing, to force the core downwardly in the casing to prevent 1ongitudinal movement.

22. In a transformer, the combination with the laminated core, of a casing therefor, clamping members which grip the core laminae, and bolts engaging said members and a cored portion of the casing at points above said members, to press the core downwardly in the casin 23. In a transformer, the combination with the laminated core, of clamping members which grip the core laminae and are formed with sockets, and a device which engages in said sockets and in cored portions in the casing, to force the core downwardly in the casing.

24:. In a transformer, the combination with the laminated core, of clamping members which grip the core laminae, each member being formed with parts of sockets, and devices which engage said sockets and cored portions of the casing, to force the core downwardly in the casing.

25. In a transformer, the combination with the laminated core, of clamping members which grip the core laminae and are formed with curved sockets, curved washers which engage the sockets, bolts which engage cored portions of the casing, and nuts on the bolts which engage said washers.

26. In a transformer, the combination with the laminated core, of clamping members which grip the core laminre, windings mounted on the core, and blocksbetween the windings and said clamping members, to secure the windings in position.

27. In a transformer structure, the combination with the laminated core and windings thereon, of a casing therefor, and clamping members which hold the core and windings in position, and are provided with legs which rest on the bottom of the transformer-casing, to permit a free circulation of the cooling fluid in the casing.

28. In a transformer structure, the combination with the laminated core and windings thereon, of a casing therefor, a bottom support for the core and windings which holds them in position, legs on said support, which are adapted to rest on the bottom of the casing, and a sling passing beneath said support between said legs, which sling supports the weight of the parts when they are moved by the sling into or out of thecasing.

29. In a transformer, the combination with the core and windings, of a tapered casing therefor, a bottom support for said core and windings, which is adapted to rest on the bottom of the casing, and lugs on said support,

which fit in the lower part of the casing, which is of smaller diameter, to prevent lateral movement.

30. The combination with a transformercasing, of a cover therefor having bolt-holes with rims around the holes, bolts extending through the holes to secure the cover to the casing, and nuts having closed ends, which engage said bolts, said parts being constructed and arranged to prevent the entrance of moisture to the inside of the casing.

31. In a transformer, the combination with the core and windings, of a two-part clamp for securing the parts so as to cover only small surfaces of said parts, and bolts for drawing theparts of said clamp together.

32. Ina transformer, the combination with the core and windings, of a bottom support for the windings, which rests on the core, and clamping members which grip said support and core, and are adapted to rest on the bottom of the transformer-casing.

33. The combination with a transformercasing, of a cover therefor havingbolt-holes with rims around the holes, bolts extending through the holes to secure the cover to the casing, and petticoated nuts having closed ends, which engage said bolts, said parts being constructed and arranged to prevent the entrance of moisture to the inside of the casing.

In Witness whereof I have hereunto set my hand this 22d day of March, 1901.

JOHN J. FRANK.

Witnesses:

BENJAMIN B. HULL, MARGARET E. WoRLLEY. 

